Ecclesiastes 1:18

For in much wisdom is much grief - The more we know of ourselves the less satisfied shall we be with our own hearts; and the more we know of mankind the less willing shall we be to trust them, and the less shall we admire them.

Be that increaseth knowledge increaseth sorrow - And why so? Because, independently of God, the principal objects of knowledge are natural and moral evils.

The Targum gives a curious paraphrase here: "The man who multiplies wisdom, when he sins and is not converted to repentance, multiplies the indignation of God against himself; and the man who adds science, and yet dies in his childhood, adds grief of heart to his relatives." A man in science; a foolish child in conduct. How pained must they be who had the expense of his education! But there are many men-children of this sort in every age and country.